Traumatic Brain Injury May Up Later Risk of Dementia

HealthDay News — A severe head injury, especially during middle age, could dramatically increase the risk for developing dementia later in life, according to research published online July 5 in PLOS Medicine.

The study included 40,639 Finnish adults between 18 and 65 who had been hospitalized with mild, moderate, or severe traumatic brain injuries (TBIs). The injuries occurred between 1987 and 2014. The researchers followed the study participants for about 11 years. The 20,703 mild TBI patients were hospitalized for less than a day. The 19,936 moderate-to-severe traumatic brain injury patients had been hospitalized for a minimum of three days.

There was no significant difference between the two groups in terms of age, educational background, or income. Though above-average dementia risk was seen among all TBI patients, the investigators found that the moderate-to-severe group faced a substantially higher risk than the mild group. The largest increase in risk was seen among those who had a TBI between ages 41 and 50. Their odds of dementia were nearly triple those of someone with a mild injury. For those who had a TBI between ages 51 and 60, the odds of dementia were doubled, the researchers found. More people in the moderate-to-severe group also developed dementia before the age of 65, compared to those in the mild group (40 versus 26%).

"After adjusting for confounding factors, we found that persons with moderate-to-severe traumatic brain injury had a 90% increased probability of developing dementia compared to persons with mild traumatic brain injury," the authors write.